INDEX TO VOLUME IV. 
(New species and new names are marked with an asterisk *.) 
Alcidamea producta, habits of 135 
Ants, formic acid produced by 28 
Aphelopus varicornis* : 143 
Aphiochaeta cavernicola* 101 
Aphiochaeta longifrons* 100 
Argyroselenis minima, visual memory of 138 
Audobon, J. J., quoted 128 
Bees as agents in pollinating flowers 13 
Bees, visual memory of 135 
Blood-root, pollination of 12 
Brues, C. T., the chemical nature of some insect secretions 22 
Brues, C. T., descriptions of parasitic hymenoptera from Cape 
Colony 103 
Brues, C. T., notes and descriptions of North American parasitic 
hymenoptera 143 
Brues, C. T., two new species of Phoridae 100 
Butterflies, as agents in pollinating flowers 15 
Camponotus, formic acid secreted by 34 
Cape Colony, parasitic hymenoptera from 103 
Carolina Grass of Parnassus, pollination of 18 
Caspian tern, notes on 113 
Ceraphron brevicornis* 146 
Ceraphron quissentensis* 147 
Ceraphron, table of North American species 144 
Ceremonial object from Michigan 160 
Chadwick, G. H., notes on Wisconsin mollusca 67 
Chemical nature of some insect secretions 22 
Chrysopa, offensive odor of 32 
Coelioxys rufitarsis, habits of 138 
Cook, O. F., quoted on the secretion of Spirobolus 26 
Cremastogaster, secretion of 32, 34 
